As one can ascertain it is often necessary to measure pressure with a high degree of accuracy and across a relatively large pressure range. Typical accuracy is specified as a percent of full scale. Therefore, even when a pressure transducer is manufactured with an extreme accuracy tolerance it may prove to be relatively inaccurate at the lower portion of the pressure range. Also it is often of interest to resolve accurately a relatively small differential pressure coupled to a fairly high line pressure. In both cases it is desirable that multiple sensing elements or multiple transducers, each of which is optimized for a specific portion of the pressure range, be employed. In the prior art, multiple pressures are measured employing multiple pressure transducers. For example, see U.S. Pat. No. 6,401,541 entitled “Multiple Pressure Sensing System” issued on Jun. 11, 2002 to Anthony D. Kurtz, an inventor herein, and assigned to Kulite Semiconductor Products, Inc. In that patent there is shown a plurality of pressure transducers where each can measure a different pressure range and are coupled to a single remote processor. In that particular patent it is a desire to measure multiple pressures by using multiple pressure transducers, but which transducers are exposed to different environments and where the pressure from each transducer is measured during a different interval. In any event, as one can ascertain from the above noted patent, there is shown multiple pressure transducers, switching devices and a microcontroller which controls the switching devices, and selects given sequences to access said transducers. The above noted patent is hereby incorporated in its entirety.
The present invention uses multiple sensing elements and an appropriate switching device to condition the signal, the internal functionality of the transducer would provide a continuous output proportional to the applied pressure over a large pressure range but with significantly enhanced accuracy. It is also understood that the assignee, Kulite, has many patents regarding the design and operation of pressure transducers in all types of environments and in all types of ranges. The present invention thus employs multiple pressure transducers which are selectively switched into operation or selectively utilized according to a different pressure range. Thus according to the present invention, one would employ multiple sensing elements each of which is optimized for a specific portion of the pressure range and each of which is selected according to that portion of the pressure range being measured.